PEAR_LOG_DEBUG messages provide detailed information
about what is happening within the internals of Auth, for example which
functions are called, logic tracking for the Authentication method, what
SQL queries are being run against the database backends.

To limit the types of messages you receive in the
Log_Observer pass either
PEAR_LOG_INFO or PEAR_LOG_DEBUG
as the first parameter to the Log_Observer. The
default is PEAR_LOG_INFO. For more information on
this filtering see the Log
Documentation.